On Fri, Mar 17, 2017 at 07:06:19PM -0700, Kuppuswamy Sathyanarayanan wrote:
> This patch adds API's to read/write/update PMC GC registers.
> PMC dependent devices like iTCO_WDT, Telemetry has requirement
> to acces GCR registers. These API's can be used for this
> purpose.
>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/intel_pmc_ipc.h | 21 ++++++++++++++
> drivers/platform/x86/intel_pmc_ipc.c | 56 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 77 insertions(+)
>
> Changes since v2:
> * Removed unused reg offset from header file.
> * Modified read/write api's signatures for better error handling
> * Added function for bit level update of gcr register.
>
> diff --git a/arch/x86/include/asm/intel_pmc_ipc.h b/arch/x86/include/asm/intel_pmc_ipc.h
> index 4291b6a..8402efe 100644
> --- a/arch/x86/include/asm/intel_pmc_ipc.h
> +++ b/arch/x86/include/asm/intel_pmc_ipc.h
> @@ -23,6 +23,9 @@
> #define IPC_ERR_EMSECURITY 6
> #define IPC_ERR_UNSIGNEDKERNEL 7
>
> +/* GCR reg offsets from gcr base*/
> +#define PMC_GCR_PMC_CFG_REG 0x08
> +
> #if IS_ENABLED(CONFIG_INTEL_PMC_IPC)
>
> int intel_pmc_ipc_simple_command(int cmd, int sub);
> @@ -31,6 +34,9 @@ int intel_pmc_ipc_raw_cmd(u32 cmd, u32 sub, u8 *in, u32 inlen,
> int intel_pmc_ipc_command(u32 cmd, u32 sub, u8 *in, u32 inlen,
> u32 *out, u32 outlen);
> int intel_pmc_s0ix_counter_read(u64 *data);
> +int intel_pmc_gcr_read(u32 offset, u32 *data);
> +int intel_pmc_gcr_write(u32 offset, u32 data);
> +int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val);
>
> #else
>
> @@ -56,6 +62,21 @@ static inline int intel_pmc_s0ix_counter_read(u64 *data)
> return -EINVAL;
> }
>
> +static inline int intel_pmc_gcr_read(u32 offset, u32 *data)
> +{
> + return -EINVAL;
> +}
> +
> +static inline int intel_pmc_gcr_write(u32 offset, u32 data)
> +{
> + return -EINVAL;
> +}
> +
> +static inline int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val)
> +{
> + return -EINVAL;
> +}
> +
> #endif /*CONFIG_INTEL_PMC_IPC*/
>
> #endif
> diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
> index 0a33592..ea5579e 100644
> --- a/drivers/platform/x86/intel_pmc_ipc.c
> +++ b/drivers/platform/x86/intel_pmc_ipc.c
> @@ -127,6 +127,7 @@ static struct intel_pmc_ipc_dev {
>
> /* gcr */
> resource_size_t gcr_base;
> + void __iomem *gcr_mem_base;
> int gcr_size;
> bool has_gcr_regs;
>
> @@ -199,6 +200,60 @@ static inline u64 gcr_data_readq(u32 offset)
> return readq(ipcdev.ipc_base + offset);
> }
>
> +int intel_pmc_gcr_read(u32 offset, u32 *data)
> +{
> + if (!ipcdev.has_gcr_regs)
> + return -EACCES;
> +
> + if (offset > PLAT_RESOURCE_GCR_SIZE)
> + return -EINVAL;
> +
we can have one function that checks the above conditions and to avoid
repetitions.
> + *data = readl(ipcdev.gcr_mem_base + offset);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(intel_pmc_gcr_read);
> +
> +int intel_pmc_gcr_write(u32 offset, u32 data)
> +{
> + if (!ipcdev.has_gcr_regs)
> + return -EACCES;
> +
> + if (offset > PLAT_RESOURCE_GCR_SIZE)
> + return -EINVAL;
> +
> + writel(data, ipcdev.gcr_mem_base + offset);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(intel_pmc_gcr_write);
> +
> +int intel_pmc_gcr_update(u32 offset, u32 mask, u32 val)
please add kernel-doc comments for this function that describes its intended
use case.
> +{
> + u32 orig, tmp;
> +
> + if (!ipcdev.has_gcr_regs)
> + return -EACCES;
> +
> + if (offset > PLAT_RESOURCE_GCR_SIZE)
> + return -EINVAL;
> +
> + orig = readl(ipcdev.gcr_mem_base + offset);
> +
> + tmp = orig & ~mask;
> + tmp |= val & mask;
> +
> + writel(tmp, ipcdev.gcr_mem_base + offset);
> +
> + tmp = readl(ipcdev.gcr_mem_base + offset);
> +
> + if ((tmp & mask) != (val & mask))
> + return -EIO;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(intel_pmc_gcr_update);
> +
> static int intel_pmc_ipc_check_status(void)
> {
> int status;
> @@ -747,6 +802,7 @@ static int ipc_plat_get_res(struct platform_device *pdev)
> ipcdev.ipc_base = addr;
>
> ipcdev.gcr_base = res->start + PLAT_RESOURCE_GCR_OFFSET;
> + ipcdev.gcr_mem_base = addr + PLAT_RESOURCE_GCR_OFFSET;
> ipcdev.gcr_size = PLAT_RESOURCE_GCR_SIZE;
> dev_info(&pdev->dev, "ipc res: %pR\n", res);
>
> --
> 2.7.4
>
--
Best Regards,
Rajneesh
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